Bridged polysilsesquioxanes, plasma

Plasma Oxidation of Hydrocarbon Templates in Bridged Polysilsesquioxanes Porous Materials by Design... 

Scheme 5. Preparation of bridged polysilsesquioxanes by sol-gel techniques followed by oxygen plasma treatment to generate porous silicas.

Plasma Oxidation of Bridged Polysilsesquioxanes. Oxidations were carried out in an inductively-coupled rf plasma (Figure 2). In a typical experiment, a ground sample of decylene-bridged polysilsesquioxane X-8 was placed in a plasma of pure oxygen (30 Watts, 138 mTorr, 2.4 standard cubic centimeters per minute (seem) p2, sample temperature 50 °C). The plasma exhibited a strong carbon monoxide photoemission. After 16 hours of plasma exposure, no carbon monoxide emission was observed and the sample was removed. When enough sample was available, the plasma experiments were repeated three times. 

Table 1. Silica Yields from Plasma Oxidation of Bridged Polysilsesquioxanes...

Figure 4. 29si MAS NMR spectra of phenylene-bridged polysilsesquioxane xerogel before oxygen plasma treatment, A, and the resulting silica after plasma treatment, B.

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